You’ll need a tab to hold the KDP, a front cover gasket, and a crankshaft to front cover seal. Other than that, it’s just wrenching. I’d adjust the timing while I was in there. As far as the head gasket goes, no need to mess with it unless you have a problem currently or you are wanting to stud it or o-ring it. But there’s no need unless you’re going after big power numbers.